Resources for memory management in embedded application

Question

How should I manage memory in my mission critical embedded application?

I found some articles with google, but couldn\'t pinpoint a really useful practical guide.

Answer 1

I've worked in a DO-178B environment (systems for airplanes). What I have understood, is that the main reason for not allowing dynamic allocation is mainly certification. Certification is done through tests (unitary, coverage, integration, ...). With those tests you have to prove that you the behavior of your program is 100% predictable, nearly to the point that the memory footprint of your process is the same from one execution to the next. As dynamic allocation is done on the heap (and can fail) you can not easily prove that (I imagine it should be possible if you master all the tools from the hardware to any piece of code written, but ...). You have not this problem with static allocation. That also why C++ was not used at this time in such environments. (it was about 15 years ago, that might have changed ...)

Practically, you have to write a lot of struct pools and allocation functions that guarantee that you have something deterministic. You can imagine a lot of solutions. The key is that you have to prove (with TONS of tests) a high level of deterministic behavior. It's easier to prove that your hand crafted developpement work deterministically that to prove that linux + gcc is deterministic in allocating memory.

Just my 2 cents. It was a long time ago, things might have changed, but concerning certification like DO-178B, the point is to prove your app will work the same any time in any context.